Apache is a public domain Web server developed by a loosely knit group of programmers. Public domain refers to any program that is not copyrighted. Public-domain software is free and can be used without restrictions. The term public-domain software is often used incorrectly to include freeware, free software that is nevertheless copyrighted. The first version of Apache, based on the NCSA httpd Web server, was developed in 1995. Because it was developed from existing NCSA code plus various patches, it was called a patchy server - hence the name Apache Server.
As a result of its sophisticated features, excellent performance, and low price - free, Apache has become the world's most popular Web server. By some estimates, it is used to host more than 50% of all Web sites in the world.
Core development of the Apache Web server is performed by a group of about 20 volunteer programmers, called the Apache Group. However, because the source code is freely available, anyone can adapt the server for specific needs, and there is a large public library of Apache add-ons. Add ons' refers to a product designed to complement another product. For example, there are numerous add-on boards available that you can plug into a personal computer to give it additional capabilities. Another term for add-on board is expansion board. In many respects, development of Apache is similar to development of the Linux operating system.
The original version of Apache was written for UNIX, but there are now versions that run under OS/2, Windows and other platforms.
Apache has been shown to be substantially faster, more stable, and more feature-full than many other web servers. Although certain commercial servers have claimed to surpass Apache's speed (it has not been demonstrated that any of these "benchmarks" are a good way of measuring WWW server speed at any rate), we feel that it is better to have a mostly-fast free server than an extremely fast server that costs thousands of dollars. Apache is run on sites that get millions of hits per day, and they have experienced no performance difficulties.
Apache is run on over 25 million Internet servers (as of December 2006). It has been tested thoroughly by both developers and users. The Apache Group maintains rigorous standards before releasing new versions of their server, and the server runs without a hitch on over one half of all WWW servers available on the Internet. When bugs do show up, we release patches and new versions as soon as they are available.
Who would have thought that a little freeware Web server could stand up to the combined onslaught of Netscape and Microsoft? Well, the Apache Project is doing quite well, thank you. By most accounts, Apache remains the No. 1 HTTP server on the Net. In fact, according to Netcraft, Apache currently hosts more sites than Microsoft and Netscape servers combined.
That's quite an accomplishment, considering that the Apache Group isn't even a company. Instead, it's a group of contributors who propose and approve changes to the code by voting.
The Apache Group and the free Apache HTTP server stand as an appealing throwback to the early, less-commercial, days of the Net when things seemed to be done for love, not for money. Free and open standards supported and maintained by the people who use them are still a good thing for the Web. And, hey, Apache is a damn fine server, too.
The Apache httpd server is a powerful, flexible, HTTP/1.1 compliant web server. It implements the latest protocols, including HTTP/1.1 (RFC2616) and is highly configurable and extensible with third-party modules. It can be customized by writing 'modules' using the Apache module API provides full source code and comes with an unrestrictive license runs on Windows NT/9x, Netware 5.x and above, OS/2, and most versions of Unix, as well as several other operating systems is actively being developed encourages user feedback through new ideas, bug reports and patches implements many frequently requested features, including:
It allows you to easily set up password-protected pages with enormous numbers of authorized users, without bogging down the server.
Allows you to set up files, or even CGI scripts, which are returned by the server in response to errors and problems, e.g. setup a script to intercept 500 Server Errors and perform on-the-fly diagnostics for both users and yourself.
Allows you to script web applications in PHP, Perl, Python and many more languages.
Allows you to say Directory Index index.html index.cgi, which instructs the server to either send back index.html or run index.cgi when a directory URL is requested, whichever it finds in the directory. Unlimited flexible URL rewriting and aliasing.Apache has no fixed limit on the numbers of Aliases and Redirects, which may be declared in the config files. In addition, a powerful rewriting engine can be used to solve most URL manipulation problems.
The ability to automatically serve clients of varying sophistication and HTML level compliance, with documents which offer the best representation of information that the client is capable of accepting.
A much requested feature, sometimes known as multi-homed servers. This allows the server to distinguish between requests made to different IP addresses or names (mapped to the same machine). Apache also offers dynamically configurable mass-virtual hosting.
You can configure Apache to generate logs in the format that you want. In addition, on most Unix architectures, Apache can send log files to a pipe, allowing for log rotation, hit filtering, real-time splitting of multiple vhosts into separate logs, and asynchronous DNS resolving on the fly.
Taking your first steps into Apache territory are a lot easier than you think. If you are a regular Unix user, you will be well prepared to set up Apache. And the Windows version has the same install procedure as any other Windows application.
The first step is to obtain a copy of Apache HTTP Server. Because it's free there's no reason not to give it a try http://httpd.apache.org . The download files are 4.2MB for the Windows version, and a little over 4.7MB for the Unix version. It is possible to write slim, high-end applications.